Email users are often prompted to give their email addresses to various organizations in order to setup an account for online transactions. Some of these organizations are potentially untrustworthy, and in return, can send unwanted communications or disseminate the email addresses to third parties, which may further abuse the email address. Blocking the original untrustworthy organization does not guard against the third parties. Moreover, revoking the email address prevents communication with legitimate senders, resulting in inconvenience for the user and entities seeking communications with the user.
One technique that attempts to defeat this problem is for the user to create a temporary address for use only with this organization, rather than exposing a user's main email address. However, in email server systems, there can be a propagation delay in creating a new email address and informing all the gateways of the new temporary address. If the user submits a new email address to an organization, the gateways at the email network system will reject any incoming emails until propagation is complete and the new email address is valid.
It is a known technique to generate one or more temporary addresses for each user in advance, before the addresses are needed. However, the user can neither select the new temporary addresses, nor can the temporary addresses be tailored to the organization to which the addresses will be submitted. Thus, the previously-generated temporary addresses are difficult for the user to remember and identify, since the machine-generated addresses do not include user-friendly nomenclature.